Stirrer



1968 J. B. ANDERSON 3,363,883

STIRRER Filed May 13, 1966 5 Sheets-Sheet 1 F 1 in lm l9 1 n 5- L9 /80 lNVENTO/i JAMES B. ANDERSON Attorneys Jan- 1 1968 J. B. ANDERSON 3,363,883

STIRRER Filed May 15, 1966 3 Sheets-$heet r7 INVENTO/F. JAMES B. ANDERSON y :3/ g g' g Af farneys Jan. 16, 1968 .J. B. ANDERSON 3,363,883

STIRRER Filed May 13, 1966 3 Sheets-Sheet 3 INVE/V r05. JAMES B. a/vomso/v A I iorneys United States Patent 3,363,883 STIRRER James B. Anderson, Mount Lebanon Township, Allegheny County, Pa, assignor to H. .i. Heinz Company, Pittshurgh, Pa, a corporation of Pennsylvania Filed May 13, 1966, Ser. No. 549,936 12 Claims. (Cl. 259-1tl9) ABSTRACT 01? THE DESCLUSURE This invention is for mixing or agitating liquids in a vessel and particularly to a stirring device for use therein. The stirrer comprises a shaft on which are mounted a plurality of blades or paddles, some of the paddles being fixed to the shaft for rotation therewith and some of the paddles being idler paddles mounted for subs antially free rotation on the shaft, the fixed rotating paddles and idler paddles alternating longitudinally of the shaft. The vessel in which the stirrer is disposed has stop members disposed in the path of the idler paddles to arrest their rotation. Some of the paddles are mounted at a pitch angle to promote agitation of the media being mixed. In one embodiment of the invention radial blades are provided at their outer ends with paddles disposed substantially parallel to the axis of the shaft.

The invention is particularly designed for use in apparatus employed in the preparation of foods where liquid or purees and the like are stirred or agitated during processing, either for the incorporation of ingredients or the cooking, concentrating or sterilizing of the liquid, but is applicable also to other industries. In the food indusry the invention is commonly used in conjunction with a vessel in which heating of the liquid is taking place so that thorough agitation is necessary to distribute heat through the product and prevent lumping, scorching or burn-on of the liquid as it heats or cooks.

Apparatus for this purpose must be capable of being readily removed from time-to-time and cleaned of all adhering material and sterilized before reuse either with a product of the same kind or some other kind.

This invention provides a vessel with an agitator wherein the agitator is designed to effect a thorough and effective stirring of the liquid and at the same time embodies all of the agitator parts on a single removable shaft so that, upon its removal, the vessel itself may be easily washed and cleaned and the stirrer be completely cleaned after removal from the vessel. It provides a stirrer comprising a shaft on which are a succession of paddles with appropriately shaped vanes. Alternate paddles are fixed on the shaft while intervening ones are free, so that when the agitator is in place in the vessel and the shaft is driven, the paddles fixed to the shaft rotate while those in between strike simple permanent abutments inside the vessel to restrain them from rotation. These abutments do not interfere with the cleaning of the inside of the vessel, and the stirrer proves the same effective turbulence or stirring action that has heretofore been secured where there are fixed vanes on the inside of the vessel to cooperate with the paddles on the rotating shaft. The construction of those paddles which are alternated between the fixed vanes is such that they, in turn, may be readily removed from the shaft for cleaning and sterilizing the stirrer.

An object of the invention is to provide a new and useful improvement in stirrers or the like.

Another object is to provide an improved mixer for viscous liquids which can easily be removed and emplaced in a container for the liquid.

These and other objects will be apparent to those 3,363,883 Patented Jan. 16, 1968 skilled in the art and more fully understood by reference to the following description, wherein:

FIG. 1 is an end elevation of a vessel with the stirrer assembly mounted therein;

FIG. 2 shows a side elevation, partly broken away, of a vessel with a stirrer assembly mounted therein;

FIG. 3 is a plan view of the stirrer assembly;

FIG. 4 is a side elevation of the stirrer assembly of FIG. 3;

FIG. 5 is an elevation partly in section of an idler paddle bearing assembly;

FIG. 6 is a side elevation of another embodiment of the invention with the vessel walls partly broken away;

FIG. 7 is an end elevation taken along the line VII VII of FIG. 6; and

FIG. 8 is a sectional end elevation of one of the idler paddles.

Referring to the drawings and first to FIGS. 14, FIGS. 1 and 2 show a stirrer assembly 10 mounted in a round bottomed keitle 11 and driven by a suitable drive means 10a. Kettle 11 is of the type shown and described in my copending application S.N. 505,522, filed Oct. 28, 1965, entitled Kettle or the Like, and assigned to the assignee of the present invention.

The stirrer assembly 10 comprises a shaft 12 on which are mounted a plurality of paddles 13, 14, and 15 longitudinally spaced along the shaft. In this embodiment each paddle is comprised of two like radial blades spaced apart on the shaft 12.

End paddies 13 are fixedly mounted on the shaft 12 for rotation therewith, and preferably the planes of the paddles are disposed at an acute angle with respect to a plane normal to the shaft longitudinal axis.

Paddles 14 are mounted on the shaft 12 on bearing assemblies 16 within which the shaft rotates, whereby the paddles 14 may idle on the shaft. The paddles 14 lie in planes containing the shaft longitudinal axis, i.e., at right angles to a plane normal to the shaft longitudinal axis. The bearing assembly 16 is comprised of a nylon bushing 17 and bushing housing sleeve 18 circumposed on the shaft 12 and refained thereon by suitable clamp members 19, the paddles 14 being fixedly secured to the sleeve 18. Both the bushing and housing are split members, i.e., they are each comprised of two semi-cylindrical portions for ease in removing and emplacing on the shaft. Bushing 17 is formed with a flange 17a at each end thereof and the housing 18 is snugly disposed between these flanges. The housing is formed with chamfered flanges 18a at each end thereof. The clamp member 19 is a suitable metal band circumposed about the flanges 18a and conforming generally to the chamfered contour of the flanges whereby the clamp is restrained against slippage in a direction longitudinally of the shaft. The clamp (FIG. 3) has two ears 1% at its opposite ends through which passes a bolt 1% held in place by nut 1% whereby the tension on the clamp may be adjusted. Each blade of the paddles 14 is secured to one of the semi-cylindrical halves of the bushing housing 18. With this construction, the paddles 14 and bearing assemblies 16 can be readily removed from the shaft for cleaning and sterilization.

The central paddle 15 is also fixedly mounted on shaft 12 for rotation therewith and is formedwith a dihedral, the two planes of which are symmetrically disposed at an acute angle wi h respect to a plane normal to the shaft longitudinal axis.

The peripheral edges of all the blades are suitably contoured to conform generally to the interior shape of the vessel and dimensioned so as to provide only a slight clearance between the blade extremities and the vessel walls.

As the shaft and the driven paddles 13 and 15 rotate in a liquid or semi-liquid media, the idler paddles 14 will also tend to rotate because of bearing friction and liquid movement. To restrain rotation of the paddles l t, there is mounted on the interior walls of the vessel 11, a plurality of projections or stop members 20, at least one such member being disposed in the path of each paddle 14 whereby these are restrained from any substantial movement in the media. By this arrangement of alternate rotating and stationary paddles there is established a continuous and rapid flow of the media between the paddles which is further enhanced by the angle of pitch in the rotating paddles.

Referring to FIGS. 6 to 8 there is shown another embodiment of the invention for use wih a right cylindrical vessel. This vessel is horizontally disposed and supported on a suitable framework 22. The stirrer assembly, designated generally as 23, is comprised of a shaft 24 rotatably mounted in the vessel and supported by the end walls of the vessel. As in the previous embodiment there are a plurality of paddles mounted on the shaft at longitudinally spaced locations with alternate rotating and stationary paddles. Paddles 25 are fixed to the shaft for rotation therewith and paddles 26 are idler paddles.

Paddles 25, as best seen in FIG. 7, are three-bladed, the blades 27 being equi-spaced about the shaft, i.e., spaced 120 apart. Each blade 27 extends outwardly to a distance short of the vessel walls, and a blade tip section 29 is mounted on the ends of each blade. The tip section is an elongated plate bolted, welded or otherwise fixed to the blade and disposed with its long axis parallel to the shaft longitudinal axis and at right angles to the radial blade, the plane of the plate being substantially in a plane through the shaft longitudinal axis. Between each two radial blades there is a strut member 30 fixed to the two arms, the resulting structure resembling in cross section, a truncated equilateral triangle symmetrical about the shaft. The struts 30 strengthen the paddles to prevent bowing and possible breaking of the paddles par ticularly when viscous liquids are being mixed.

The idler paddles 26 are mounted on the shaft 24 on bearing assemblies 31, similar to those previously described, whereby the paddles 26 may rotate independently of the shaft. As best seen in FIG. 8 these paddles have two blades 32 spaced 180 apart. The blades 32 are shaped much like the blades 27, that is, they are T- shaped, having a radial arm 33 with a tip section 34. The blades 32, however, extend radially outward only to a distance whereby the tip sections 29 of the adjacent rotating paddles 25 overlap the sections 34 of paddles 26, i.e., the cylinders of revolution defined by the paddles 2.6 are concentric with, of lesser radii than, and overlapped by the cylinders of revolution defined by the adjacent paddles 25.

Extending radially outwardlyfrom and fixed to one blade section of each paddle 26 there is a finger 35 which projects between the paths of revolution of the ends of adjacent blade sections 29 to engage a stop member 36 on the inner wall of vessel 21, disposed in the path of revolution of the finger 35. Thus, paddles 25 may rotate through a maximum of one revolution before fingers 35 engage stops 36 to restrain further turning of paddles 26.

By removing one end wall of the vessel 21 the entire stirrer assembly may be removed therefrom as a unit for cleaning and maintenance. Where the media being mixed comprises food products it is preferable that the vessel and stirrer assemblies be made of stainless steel or the like and that all welds be continuous and smooth-finished to minimize the entrapping of particles in and around the various parts.

It may be seen therefore, that the invention provides a greatly improved stirrer assembly which effectively agitates liquids, especially viscous liquids and semi-liquids, by the rapid and continuous flow over, around and between the stirrer paddles, and that the entire stirrer assembly may readily be removed from and emplaced in a vessel as a unit.

While several embodiments of the invention have been described, it will be apparent to those skilled in the art that various modifications in the construction and arrangement of parts are possible within the scope and spirit of the invention.

1 claim:

1. In combination with a container for liquids, a stirrer assembly comprising,

(a) a shaft rotatably mounted on and extending into the container,

(b) means for rotating the shaft,

(c) a plurality of paddles mounted on the shaft at longitudinally spaced locations along the shaft for engagement with the liquid contents, at least one of the paddles being fixed to the shaft for rotation therewith, at least one idler paddle next adjacent a fixed paddle and mounted for substantially free rotation on the shaft, and

(d) a projection on the interior of the container extending into the path of each idler paddle whereby the latter is restrained against rotation on contacting the projection.

2. The combination as defined in claim 1, wherein there are at least two fixed paddles with one idler paddle therebetween.

3. The combination as defined in claim 2, wherein the paddles fixed to the shaft are disposed at a pitch angle with respect to the shaft axis of rotation whereby to promote the flow of the liquid in a direction longitudinally of the shaft.

4. The combination as defined in claim 1, wherein the container has a generally cylindrical wall portion and the shaft is disposed diametrically across the cylindrical portion.

5. The combination as defined in claim 1, wherein the container is a right cylinder and the shaft is centrally disposed within the cylinder with its axis substantially coextensive with the cylinder axis.

6. The combination as defined in claim 5, wherein the paddles comprise radial blades extending outwardly from the shaft and elongated plate portions on the ends of the blades, the plate portions being longitudinally disposed with the long axes parallel to the shaft.

7. The combination as defined in claim 6, wherein the rotating paddles comprise at least three radial blades equiangularly spaced about the shaft and a strut member connecting adjacent blades to each other at a location on the blades radially spaced from the shaft.

8. The combination as defined in claim 6, wherein the cylinder of revolution defined by the plate portions of each rotating paddle, is of greater radius than the radius of each idler paddle.

9. The combination as defined in claim 1, including a bearing assembly for mounting each of the idler paddles on the shaft, each bearing assembly comprising,

(a) a bushing on the shaft formed by two semi-cylindrical portions,

(b) a bushing housing around the bushing, formed by two semi-cylindrical portions,

(0) a blade member connected to and extending radially from each of the bushing housing portions, and

(d) clamp means around the bushing housing to hold the bushing and housing in position on the shaft.

10. The combination as defined in claim 9, wherein the bushing is formed with an outwardly turned flange at its opposite ends, the bushing housing is disposed intermediate the bushing flanges, the bushing housing is formed with an outwardly turned chamfered flange at its opposite ends, and the clamp means comprises a band around each of the housing flanges, which band is shaped to conform generally to the chamfered flange, and means for adjusting the tension on each band.

11. In combination with a generally right-cylindrical container for liquids, a stirrer assembly comprising,

(a) a shaft rotatably mounted on and extending into 5 6 the container with its longitudinal axis on the longi- (a) a shaft rotatably mounted on and extending into tudinal axis of the cylinder, Container, (b) a plurality of paddles mounted on the shaft at means Totaling the shaft,

longitudinally spaced locations therealong, some of (c) at 1aStthree Paddles {mounted on the Shaft at longithe paddles being fixed to the shaft for rotation there- 5 mdmany SPFwed locgtlofls along the shaft for with, other of the paddles being idler paddles mountgagement wlth the hquld contents at least one of the paddles being fixed to the shaft for rotation therewith, at least one idler paddle next adjacent a fixed paddle and mounted for substantially free rotation on the shaft, the Whole of the set of three paddles being so arranged that the fixed and idler paddles alternate ed for rotation on the shaft independently of the shaft, the rotating paddles and idler paddles being arranged alternately along the shaft, each of the paddles comprising a plurality of equiangularly 10 spaced radial blades mounted on the shaft, an elonalong the shaft.

gated plate member mounted on the end of each such radial blade with the long axis thereof parallel to References Cited the shaft axis, the rotating paddles and idler paddles 15 UNITED STATES PATENTS being so arranged that the elongated plates of adja- 1 432 323 10/1922 Dulce 259 178 X cent paddles overlap longitudinally with the plates 1888957 11/1932 i; X of the rotating paddles describing cylinders of revo- 2:015:244 9 /1935 stokdale ISL S: X lulion about the idler p 335 579 5 19 5 Lasar 259 11O X 12. In combination with a container for liquids, a 29 stirrer assembly comprising, ROBERT W. JENKINS, Primary Examiner. 

